Black dog of depression adopts no prejudice as it reaches into heroic and humdrum lives
The day before he threw himself under a speeding train, Robert Enke was pictured smiling in a Hanover cafe with his daughter Leila on his lap.
It is the last photograph taken of the German goalkeeper and one in which he looks blissfully happy.
The belief is that he had already decided to kill himself as he posed at that moment for wife, Teresa, who to this day keeps that compelling image on a kitchen wall.
Enke's struggle with depression wasn't broadly known and his death convulsed a game full of people who imagined they had some kind of connection with him. "How could we not see?" became a recurring question.
He was 32 when he died in 2009, had been voted the Bundesliga's top goalkeeper for the previous season and looked to be finally established as No 1 for the German national team after years as understudy to Jens Lehmann. From a distance, Enke seemed to communicate the perfect study of professional composure.
But he had been struggling with his mental health for six years and it is thought the death of his infant daughter Lara in '06 because of a heart defect chronically compounded that struggle.
In A Life Too Short, the breathtakingly beautiful book written by his friend Ronald Reng, that paradox between the private and public lives of an individual is addressed and specifically the "consideration for others" so often denied top-class sports people.
Reng writes: "Robert suffered from this, as do many other footballers who notice that certain coaches - and even more than coaches, the public - see concern or empathy as a weakness in a footballer."
In other words, his sport demanded of Enke an almost robotic persona, indifferent to what might have existed behind the mask.
When Gary Speed took his own life, football was equally baffled.
So many of the tributes focused on the multiple blessings in the Welshman's life as if they should somehow have inoculated him against depression.
As if, no matter an individual's emotional infirmities, the material world might offer a soft landing.
Stereotype is a natural hazard of serious sport.
It becomes human to dehumanise what we see, to presume upon the robust mental health of participants on the skewed basis that those who have uncommon talent or physical advantages on general society must logically have deeper psychological reserves too.
But any performance-based industry must, by its nature, peel back uncomfortable layers of an individual.
And, when identity is so intimately linked to a public persona, the lure of self-deception simply has to be immense - the trap of acting out a role that satisfies the market as distinct from living a life that is anything but superficially fulfilling.
There is certainly something profoundly uncomfortable about watching Tyson Fury's rather manic bravado in the media eye of late: all those V-signs and cartoon faces, the vulgar Twitter meltdowns.
Most recent speculation, as he vacated his world titles, seemed to focus upon when we might see him box again, as if only the ring could deliver true salvation.
There were even suggestions that ITV might be lining him up with a big-money offer to enter the jungle as part of the I'm a Celebrity, Get me out of Here cast. A source 'close' to Fury reputedly told one English tabloid: "A good run on the show would improve his image."
Read that line and try to reconcile it with any sense of care towards a palpably troubled 28-year-old whose self-destructive instincts seem to be steadily darkening. Never mind the man, in other words, just make sure to service the brand.
One of the more remarkable stories in Michael Calvin's Living on a Volcano - The Secrets of Surviving as a Football Manager, is that of Martin Ling, whose depression forced him to quit after just 56 days in charge of Swindon last year.
Ling is especially interesting because, as a player, he was almost stereotypically laddish in his behaviour, a 'mouthy Cockney' as he himself remembers.
"Part of your survival mechanism in football is humour," he tells Calvin. "I was always social secretary. I was the centre of every joke."
But behind the front, Ling was a softer, more complex person than he imagined his profession could ever tolerate. And management exposed that person brutally, Ling sometimes left crying uncontrollably over the impact his decision-making was having on players' lives.
He suffered a mental breakdown at Torquay in 2013, but the warning signs had been building long before that. In his previous managerial role at Cambridge United, Ling reported sick one morning in '09 after discovering he had forgotten to gel his hair.
"The tiniest setback was becoming a massive anxiety," he recalled recently. That incident led to him taking ten says off work, citing "a virus".
He spent five weeks in The Priory after the Torquay breakdown and eventually underwent electroshock treatment for his condition, a kind of barbaric last resort in his efforts to feel better.
Ling believes it has worked too, albeit public knowledge of his difficulties will probably make it difficult for him to get a full-time job in professional football again.
He describes those difficulties as "the coffee stain on my CV", yet is motivated to put them in the public domain on the basis that "talking about all the grisly details might help someone else spot the signs".
His candour is admirable and, thankfully, increasingly commonplace.
One of the publishing success stories in Ireland this year has been Alan O'Mara's wonderful The Best Is Yet To Come - a memoir about football and finding a way through the dark.
The Cavan GAA goalkeeper is also a GPA wellbeing ambassador and writes with terrific lucidity about his own struggles with depression and how they pushed him towards suicidal instinct.
O'Mara recalls seriously contemplating steering his car into a concrete wall once and says that the image which ultimately prevented him from doing so was a visualisation of his parents attending his funeral.
Given the traditional purchase put on aggression and machismo within a GAA dressing-room, O'Mara's openness has rightly earned him kudos.
And last Saturday night, in the Abbey Hotel, Donegal Town, another profoundly personal GAA book set sail with the launch of Donal Reid's Confessions of a Gaelic Footballer.
Reid will be remembered as a tough, implacable wing-back on the Donegal team that won the county's first All-Ireland in 1992 and, to mark the 25th anniversary of that achievement, he has put his name to a book about far more than football.
In it, he recounts his own experience with depression and how, during a charity trip to a Romanian orphanage, a sudden attack almost caused him to jump to his death from a bridge over the river Siret.
"I had one foot on the wall of the bridge and was pulling up my other foot when I heard a voice calling at me 'Donal are you ok?'"
That voice belonged to a fellow charity worker he now remembers as his "guardian angel".
For a man whose public persona had always been that of an indestructible ground-breaker in sport, Reid's efforts to assimilate the wretched conditions in which he found these Romanian orphans living pitched him into a sudden nervous breakdown.
He describes it as "my own personal living hell", charting the subsequently complex journey to recovery.
"For me, the pain was unbearable," he says. "It was there every minute of every hour of every day.
The only respite I had was at night when I took a sleeping tablet. The pain was gone for that period, but it didn't last long enough.
"During the day, I waited for night-time because I knew that I was going to get relief."
Reid's book, from which all proceeds will go to Pieta House, is another stark reminder that, behind the headlines, sports heroes are flesh and bone too.